Is a cracked manifold dangerous to drive and is it expensive to fix?

Yes, a cracked manifold can be dangerous to drive because it may lead to exhaust leaks, which can introduce harmful gases into the vehicle's cabin and affect engine performance. Additionally, it can cause overheating and further engine damage if not addressed. Repair costs can vary significantly depending on the vehicle make and model, as well as the extent of the damage, but it can be quite expensive due to labor and parts involved in replacing the manifold.